Glue and Magnets - What Works

I have tried all kinds of glues (epoxies, super glue, gorrilla glue...) to get my magnets to adhere to cache containers, especially the plastic types. They work great for a little while, then it seems they all come unattached. Any of my fellow cacher friends out there have any tips on glue that you use that works for LONG periods of time??? Any help is appreciated!

I've tried the marine epoxy and so far it's working on one of my hides where I'm attaching a baby soda bottle to an aluminum fence post cap. The problem is that stuff is like $9.00 a tube and after it is opened - it doesn't last!

Wow, sounds like you better have enough supplies to build a BUNCH of caches if you are going to use that glue!

Personally, I've had really good luck with Gorilla Glue when using rare earth magnets. But when using those black button magnets you get at hobby lobby I haven't found anything that sticks to them worth a darn!